Thank you all for answers. (Have been really busy yesterday and about to get out again now before it gets too hot, so this will be short!)
Booboostoo you've hit nail on head with what's going through my mind at the moment! I'd more or less made up mind to step back from this very sweet horse altogether yesterday and regard this as not my problem when YO told me about cortisone injections - seemingly as fairly straightforward solution...
And yes, it's addressing the behaviour (which isn't terrible, just slight nappiness, but still doesn't seem OK to me to choose to treat is as cheekiness if it's really caused by pain).
And expense of addressing this for someone else's horse.
Thank you for thoughts and advice - and pointers for vets - (though yard has very good one).
If you are worried about a physical reason for her behaviour you need to address that before you can think of riding her through it.
KS is contentious because some horses may have pain and suggestive x-rays but the root of their problems is still not KS. The definitive way to diagnose KS is a scintigraphy but that can be quite expensive. If you suspect KS and the x-rays are indicative of KS you can also try steroid injections. If there is improvement then the cause is likely to be KS, if there is no improvement then it's not KS.
Steroids will give relief in KS cases but their effect is generally temporary (they offer relief from inflammation and if during that time you can get the horse to work long and low it will help improve its top line and therefore alleviate the KS, but long term the pain is likely to return).
The long term solution to KS is an operation but there is a high risk of infection and a long period of box rest rehab. Cotts Equine do a new verion of the operation which is done standing up, laparoscopically, and witha much shorted box rest period (6 weeks, with walking in hand from the first few days).
However, if the horse also has SI it could have a multitude of problems and you may go from fixing one to having to tackle another.
How reasonable is it for you to take on all these investigations for a loan horse? One possible way to go is to put the horse on a painkiller trial for a couple of weeks (Danillon is the drug usually used in these cases) and see if there is improvement. If she is a lot better than the cause of her problems is pain and you need to decide how much money, time and effort you want to spend getting right a loan horse. If she is no better that suggests (although not 100%) that the cause is not physical but behavioural in which case you may want to get a good instructor to come out with you and give you some pointers on how to ride her when she plays up.
Here I am! The only way you will know for sure is if you have an Xray - if you are concerned then I would look into having one asap and at least that way you'll know where you stand.
Whereabouts are you? I can recommend Three Counties Equine at Tewkesbury. My TB was diagnosed last autumn and having had successful pain relief with steroids, has just had a ligament resection which is a newer type of surgery from the usual (which involves cutting out sections of bone) and is on week 3 of rehab.
It's a vile thing, but isn't always the end of the road......but arrange an xray otherwise you'll spend every ridden moment worrying about it (been there!).
I know KS is supposedly a fashionable illness, over diagnosed, etc., but I'd really appreciate any advice you can give me.
I'm loaning a lovely 14 yo TB.
She's been with me a month, and we've been taking things very slowly, mostly because she's felt very stiff and weak when ridden, particularly in school, and more so, to my mind, than feels right as part of general unfitness/lack of schooling. Also she was flinching a bit sometimes when groomed - just not right; wobbly and spooky when ridden out, napping a bit. I thought the napping etc normal for horse at new yard, new place, a few cheeky habits, etc. But just didn't feel right.
She passed 2 stage vetting this week, but with vet commenting on her muscular pain and weakness (back). Physio saw her yesterday, said her back's in really poor shape and high probability of KS or other underlying problem - also possibly sacro(?) problems.
I took her for gentle hack today (as advised), lunging tomorrow, plan to go on to pole work, etc.
But I spent today's hack in a total state of worry, thinking every flick of her ears/tail, every tiny spook was pain-related, and worrying about what's in store for us in future.
I don't know what my question is, really... Just wondering whether anyone's had similar experience or can offer advice.